Fabrikasi Beads Kitosan/Alginat-Karbon Aktif Dari Kulit Pisang Kepok (Musa acuminata) Untuk Adsorpsi Metilen Biru

Inna Tahalliah, Dr.Sc. Ari Dwi Nugraheni, S.Si., M.Si.

2026 | Skripsi | FISIKA

Pada penelitian ini, beads komposit kitosan/alginat-karbon aktif (CSA-AC) dari kulit pisang kepok (Musa acuminata) difabrikasi serta karakteristik dan kinerjanya dalam adsorpsi metilen biru (MB) dianalisis. AC disintesis melalui karbonisasi pada suhu 500°C setelah aktivasi ZnCl? 15%, kemudian diimobilisasi dalam matriks CSA melalui metode ionotropic gelation dengan CaCl? 4%. Variabel yang dikaji meliputi konsentrasi AC dalam beads (2%, 4%, dan 6%) serta massa beads (0,1 g, 0,3 g, dan 0,5 g). Uji adsorpsi dilakukan secara batch menggunakan larutan MB 10 mg/L selama 60 menit, dan konsentrasi sisa dianalisis menggunakan UV-Visible Spectrophotometer (UV-Vis) pada lamda maksimal 664 nm. Hasil karakterisasi Scanning Electron Microscopy (SEM) menunjukkan morfologi permukaan beads CSA-AC yang kasar, heterogen, dan berongga. Persentase adsorpsi tertinggi diperoleh pada variasi CSA-AC 6% sebesar 85,60%, sedangkan pada uji variasi massa diperoleh sebesar 89,44% pada massa 0,5 g. Berdasarkan analisis kinetika, model pseudo-second order (PSO) lebih sesuai dibandingkan pseudo-first order (PFO), ditunjukkan oleh nilai R² PSO yang mendekati 1 dan q_e teoritis yang mendekati q_e eksperimen. Nilai R² PFO yang juga mendekati 1 mengindikasikan mekanisme adsorpsi fisika dan kimia berperan bersamaan, dengan interaksi kimia sebagai tahap penentu laju.

In this study, chitosan/alginate-activated carbon (CSA-AC) composite beads from kepok banana peel (Musa acuminata) were fabricated, and their characteristics and performance in methylene blue (MB) adsorption were analyzed. The AC was synthesized through carbonization at 500°C following ZnCl? 15?tivation, and subsequently immobilized in the CSA matrix via the ionotropic gelation method using CaCl? 4%. The variables examined included AC concentration within the beads (2%, 4%, and 6%) and bead mass (0.1 g, 0.3 g, and 0.5 g). The adsorption test was conducted in batch mode using a 10 mg/L MB solution for 60 minutes, and the residual concentration was analyzed using a UV-Visible Spectrophotometer (UV-Vis) at lamda maximal 664 nm. Scanning Electron Microscopy (SEM) characterization revealed that the CSA-AC beads exhibited a rough, heterogeneous, and porous surface morphology. The highest adsorption percentage was obtained at the CSA-AC 6% variation, reaching 85.60%, while the mass variation test yielded the highest value of 89.44% at 0.5 g. Based on kinetic analysis, the pseudo-second order (PSO) model fitted the data better than the pseudo-first order (PFO) model, as indicated by the R² PSO value approaching 1 and the theoretical q_e closely matching the experimental q_e. The R² PFO value, which also approached 1, indicates that both physical and chemical adsorption mechanisms occurred simultaneously, with chemical interaction acting as the rate-determining step.

Kata Kunci : Adsorpsi, Beads kitosan/alginat, Karbon aktif, Kulit pisang kepok, Metilen biru